4,4′-Dihydroxydiphenylsulfone (hereinafter occasionally referred to as 4,4′-DDS), 2,4′-dihydroxydiphenylsulfone (hereinafter occasionally referred to as 2,4′-DDS) and mixtures thereof are of use as materials for engineering polymers, color developers for heat-sensitive paper, and the like. Trihydroxytriphenyldisulfone (hereinafter occasionally referred to as TTDS) and coloring impurities generated during the reactions for producing dihydroxydiphenylsulfone cause the properties of dihydroxydiphenylsulfone to be impaired. Therefore, a process for the effective removal thereof has been sought.